1. Field of the Invention
This invention relates generally to improvements in spray-forming devices, and more particularly to a spray-forming output device for fluidic oscillators and to a sprayer device employing a fluidic oscillator in combination with the spray-forming output device.
2. Prior Art and Other Considerations
Fluidic oscillator devices for the generation of oscillating or pulsating fluid output patterns have been known in the art for some time (for instance, see U.S. Pat. Nos. 3,016,066; 3,432,102; 3,507,275; 4,052,002; 4,151,955; 4,184,636; 4,463,904; 4,721,251). In all of these patents a fluid jet is caused to oscillate by means of fluid interaction using no moving parts, and the resulting fluid stream is issued into the ambient environment to disperse the fluid therein. Other fluidic oscillator devices, such as for instance disclosed in U.S. Pat. Nos. 3,563,462; 3,741,481; and 4,184,636 issue discrete pulses of fluid in alternation from two or more outlet openings.
Most known fluidic oscillators, such as for example those noted in the foregoing, rely internally upon two-dimensional flow patterns and interactions thereof. Consequently, many of these oscillators inherently tend to produce two-dimensional output patterns from their outlets. In this connection, the here used term "two-dimensional" is intended to mean an output pattern that originates in a side-to-side oscillation of a stream in a plane and that results in a substantially flat, fan-shaped, planar spray pattern with a relatively small thickness perpendicular to the plane of the spray pattern.
Many applications for spray-producing devices, however, require spray dispersal in a three-dimensional pattern. Thus, uses in which the spray is desired to cover an area can be well served only with spray-producing devices that issue a spray pattern having a conical, pyramidal or similar three-dimensional shape. Oscillatory spray can be rather advantageous in many such applications, for instance due to the resulting much-improved cleaning effects upon impact surfaces (as opposed to the effects of steady spray). Other advantageous effects of oscillatory spray include also improved heat transfer, improved wetting, massaging and vibrational effects, and the like.
Fluidic oscillator devices for producing three-dimensional spray patterns have been also disclosed, for instance, in U.S. Pat. Nos. 4,151,955 and 4,184,636.
In general, prior art fluidic oscillator devices for producing three-dimensional spray patterns have suffered from certain performance limitations with respect to spray-angle extent and spray distribution within the pattern. For instance, three-dimensional spray-pattern angles (in every direction across the pattern) much beyond 20-30 degrees have been difficult, if not impossible, to achieve, and relatively even spray distribution across the pattern, especially for wider angles, has been virtually unattainable in most situations. Large pattern angles in one direction and small angles in another (orthogonal) direction across the pattern have not been difficult to obtain with prior art devices. Useful conical spray patterns, for instance, with cone angles significantly larger than about 30 degrees, however, have not been achievable, particularly with even spray distribution in every direction across the pattern. Similar limitations have applied to pyramidal spray patterns.
Such limitations of the prior art are also especially restricting in applications wherein spatial design constraints or other requirements demand issuing a three-dimensional spray pattern substantially orthogonally with respect to the plane of the fluidic oscillator channel configuration. In this respect, it is often desirable to house the fluidic oscillator spray device such as to need as little as possible space or distance in the direction of the issuing spray. Hence, issuing the spray orthogonally to the plane of the oscillator channel configuration is desirable in such situations.
The spray-forming output device of the present invention avoids difficulties of the aforementioned kind and provides three-dimensional spray patterns while facilitating relatively large spray angles and substantially even spray distribution across the spray pattern.
Accordingly, an important overall feature of the invention is the provision of an improved spray-forming output device for fluidic oscillators and an improved method of channelling oscillating output flow from a fluidic oscillator to and through one or more outlets to generate a relatively wide-angle three-dimensional spray pattern of generally even spray distribution.